diff --git a/src/main/kotlin/com/back/koreaTravelGuide/common/exception/GlobalExceptionHandler.kt b/src/main/kotlin/com/back/koreaTravelGuide/common/exception/GlobalExceptionHandler.kt
index 40610c1..8d0f674 100644
--- a/src/main/kotlin/com/back/koreaTravelGuide/common/exception/GlobalExceptionHandler.kt
+++ b/src/main/kotlin/com/back/koreaTravelGuide/common/exception/GlobalExceptionHandler.kt
@@ -14,6 +14,7 @@ import org.springframework.web.bind.annotation.ExceptionHandler
  * @Valid 검증 실패 → 400
  * throw IllegalArgumentException("메시지") → 400
  * throw NoSuchElementException("메시지") → 404
+ * throw IllegalStateException("메시지") → 409
  * 기타 모든 예외 → 500
  */
 @ControllerAdvice
@@ -41,6 +42,12 @@ class GlobalExceptionHandler {
         return ResponseEntity.status(HttpStatus.NOT_FOUND).body(ApiResponse(ex.message ?: "데이터를 찾을 수 없습니다"))
     }
 
+    @ExceptionHandler(IllegalStateException::class)
+    fun handleIllegalState(ex: IllegalStateException): ResponseEntity<ApiResponse<Void>> {
+        logger.warn("부적절한 상태: {}", ex.message)
+        return ResponseEntity.status(HttpStatus.CONFLICT).body(ApiResponse(ex.message ?: "요청을 처리할 수 없는 상태입니다"))
+    }
+
     @ExceptionHandler(Exception::class)
     fun handleGenericException(
         ex: Exception,
diff --git a/src/main/kotlin/com/back/koreaTravelGuide/common/security/AuthenticationExtensions.kt b/src/main/kotlin/com/back/koreaTravelGuide/common/security/AuthenticationExtensions.kt
new file mode 100644
index 0000000..e708be6
--- /dev/null
+++ b/src/main/kotlin/com/back/koreaTravelGuide/common/security/AuthenticationExtensions.kt
@@ -0,0 +1,10 @@
+package com.back.koreaTravelGuide.common.security
+
+import org.springframework.security.core.Authentication
+
+fun Authentication.getUserId(): Long {
+    if (principal is Long) {
+        return principal as Long
+    }
+    throw IllegalStateException("인증된 사용자 ID를 찾을 수 없거나 타입이 올바르지 않습니다.")
+}
diff --git a/src/main/kotlin/com/back/koreaTravelGuide/domain/auth/controller/AuthController.kt b/src/main/kotlin/com/back/koreaTravelGuide/domain/auth/controller/AuthController.kt
index b750e04..7312ee4 100644
--- a/src/main/kotlin/com/back/koreaTravelGuide/domain/auth/controller/AuthController.kt
+++ b/src/main/kotlin/com/back/koreaTravelGuide/domain/auth/controller/AuthController.kt
@@ -1,6 +1,7 @@
 package com.back.koreaTravelGuide.domain.auth.controller
 
 import com.back.koreaTravelGuide.common.ApiResponse
+import com.back.koreaTravelGuide.common.security.getUserId
 import com.back.koreaTravelGuide.domain.auth.dto.request.UserRoleUpdateRequest
 import com.back.koreaTravelGuide.domain.auth.dto.response.AccessTokenResponse
 import com.back.koreaTravelGuide.domain.auth.dto.response.LoginResponse
@@ -10,7 +11,7 @@ import jakarta.servlet.http.HttpServletRequest
 import jakarta.servlet.http.HttpServletResponse
 import org.springframework.beans.factory.annotation.Value
 import org.springframework.http.ResponseEntity
-import org.springframework.security.core.annotation.AuthenticationPrincipal
+import org.springframework.security.core.Authentication
 import org.springframework.web.bind.annotation.CookieValue
 import org.springframework.web.bind.annotation.PostMapping
 import org.springframework.web.bind.annotation.RequestBody
@@ -45,9 +46,10 @@ class AuthController(
     @Operation(summary = "신규 사용자 역할 선택")
     @PostMapping("/role")
     fun updateUserRole(
-        @AuthenticationPrincipal userId: Long,
+        authentication: Authentication,
         @RequestBody request: UserRoleUpdateRequest,
     ): ResponseEntity<ApiResponse<LoginResponse>> {
+        val userId = authentication.getUserId()
         val loginResponse = authService.updateRoleAndLogin(userId, request.role)
         return ResponseEntity.ok(ApiResponse("역할이 선택되었으며 로그인에 성공했습니다.", loginResponse))
     }
diff --git a/src/main/kotlin/com/back/koreaTravelGuide/domain/rate/controller/RateController.kt b/src/main/kotlin/com/back/koreaTravelGuide/domain/rate/controller/RateController.kt
index ca617d4..0324088 100644
--- a/src/main/kotlin/com/back/koreaTravelGuide/domain/rate/controller/RateController.kt
+++ b/src/main/kotlin/com/back/koreaTravelGuide/domain/rate/controller/RateController.kt
@@ -1,6 +1,7 @@
 package com.back.koreaTravelGuide.domain.rate.controller
 
 import com.back.koreaTravelGuide.common.ApiResponse
+import com.back.koreaTravelGuide.common.security.getUserId
 import com.back.koreaTravelGuide.domain.rate.dto.GuideRatingSummaryResponse
 import com.back.koreaTravelGuide.domain.rate.dto.RateRequest
 import com.back.koreaTravelGuide.domain.rate.dto.RateResponse
@@ -10,7 +11,7 @@ import org.springframework.data.domain.Page
 import org.springframework.data.domain.Pageable
 import org.springframework.http.ResponseEntity
 import org.springframework.security.access.prepost.PreAuthorize
-import org.springframework.security.core.annotation.AuthenticationPrincipal
+import org.springframework.security.core.Authentication
 import org.springframework.web.bind.annotation.GetMapping
 import org.springframework.web.bind.annotation.PathVariable
 import org.springframework.web.bind.annotation.PutMapping
@@ -26,10 +27,11 @@ class RateController(
     @Operation(summary = "가이드 평가 생성/수정")
     @PutMapping("/guides/{guideId}")
     fun rateGuide(
-        @AuthenticationPrincipal raterUserId: Long,
+        authentication: Authentication,
         @PathVariable guideId: Long,
         @RequestBody request: RateRequest,
     ): ResponseEntity<ApiResponse<RateResponse>> {
+        val raterUserId = authentication.getUserId()
         val rate = rateService.rateGuide(raterUserId, guideId, request.rating, request.comment)
         return ResponseEntity.ok(ApiResponse("가이드 평가가 등록되었습니다.", RateResponse.from(rate)))
     }
@@ -37,10 +39,11 @@ class RateController(
     @Operation(summary = "AI 채팅 세션 평가 생성/수정")
     @PutMapping("/aichat/sessions/{sessionId}")
     fun rateAiSession(
-        @AuthenticationPrincipal raterUserId: Long,
+        authentication: Authentication,
         @PathVariable sessionId: Long,
         @RequestBody request: RateRequest,
     ): ResponseEntity<ApiResponse<RateResponse>> {
+        val raterUserId = authentication.getUserId()
         val rate = rateService.rateAiSession(raterUserId, sessionId, request.rating, request.comment)
         return ResponseEntity.ok(ApiResponse("AI 채팅 평가가 등록되었습니다.", RateResponse.from(rate)))
     }
@@ -48,9 +51,8 @@ class RateController(
     @Operation(summary = "내가 받은 가이드 평가 조회")
     @GetMapping("/guides/my")
     @PreAuthorize("hasRole('GUIDE')")
-    fun getMyGuideRatings(
-        @AuthenticationPrincipal guideId: Long,
-    ): ResponseEntity<ApiResponse<GuideRatingSummaryResponse>> {
+    fun getMyGuideRatings(authentication: Authentication): ResponseEntity<ApiResponse<GuideRatingSummaryResponse>> {
+        val guideId = authentication.getUserId()
         val summary = rateService.getMyGuideRatingSummary(guideId)
         return ResponseEntity.ok(ApiResponse("내 가이드 평점 정보를 조회했습니다.", summary))
     }
diff --git a/src/main/kotlin/com/back/koreaTravelGuide/domain/user/controller/GuideController.kt b/src/main/kotlin/com/back/koreaTravelGuide/domain/user/controller/GuideController.kt
index 5944fb7..b96d522 100644
--- a/src/main/kotlin/com/back/koreaTravelGuide/domain/user/controller/GuideController.kt
+++ b/src/main/kotlin/com/back/koreaTravelGuide/domain/user/controller/GuideController.kt
@@ -1,6 +1,7 @@
 package com.back.koreaTravelGuide.domain.guide.controller
 
 import com.back.koreaTravelGuide.common.ApiResponse
+import com.back.koreaTravelGuide.common.security.getUserId
 import com.back.koreaTravelGuide.domain.guide.service.GuideService
 import com.back.koreaTravelGuide.domain.user.dto.request.GuideUpdateRequest
 import com.back.koreaTravelGuide.domain.user.dto.response.GuideResponse
@@ -8,7 +9,7 @@ import io.swagger.v3.oas.annotations.Operation
 import io.swagger.v3.oas.annotations.tags.Tag
 import org.springframework.http.ResponseEntity
 import org.springframework.security.access.prepost.PreAuthorize
-import org.springframework.security.core.annotation.AuthenticationPrincipal
+import org.springframework.security.core.Authentication
 import org.springframework.web.bind.annotation.GetMapping
 import org.springframework.web.bind.annotation.PatchMapping
 import org.springframework.web.bind.annotation.PathVariable
@@ -42,9 +43,10 @@ class GuideController(
     @PreAuthorize("hasRole('GUIDE')")
     @PatchMapping("/me")
     fun updateMyGuideProfile(
-        @AuthenticationPrincipal guideId: Long,
+        authentication: Authentication,
         @RequestBody request: GuideUpdateRequest,
     ): ResponseEntity<ApiResponse<GuideResponse>> {
+        val guideId = authentication.getUserId()
         val updatedGuideProfile = guideService.updateGuideProfile(guideId, request)
         return ResponseEntity.ok(ApiResponse("가이드 정보가 성공적으로 수정되었습니다.", updatedGuideProfile))
     }
diff --git a/src/main/kotlin/com/back/koreaTravelGuide/domain/user/controller/UserController.kt b/src/main/kotlin/com/back/koreaTravelGuide/domain/user/controller/UserController.kt
index 32d1fab..8cde527 100644
--- a/src/main/kotlin/com/back/koreaTravelGuide/domain/user/controller/UserController.kt
+++ b/src/main/kotlin/com/back/koreaTravelGuide/domain/user/controller/UserController.kt
@@ -1,12 +1,13 @@
 package com.back.koreaTravelGuide.domain.user.controller
 
 import com.back.koreaTravelGuide.common.ApiResponse
+import com.back.koreaTravelGuide.common.security.getUserId
 import com.back.koreaTravelGuide.domain.user.dto.request.UserUpdateRequest
 import com.back.koreaTravelGuide.domain.user.dto.response.UserResponse
 import com.back.koreaTravelGuide.domain.user.service.UserService
 import io.swagger.v3.oas.annotations.Operation
 import org.springframework.http.ResponseEntity
-import org.springframework.security.core.annotation.AuthenticationPrincipal
+import org.springframework.security.core.Authentication
 import org.springframework.web.bind.annotation.DeleteMapping
 import org.springframework.web.bind.annotation.GetMapping
 import org.springframework.web.bind.annotation.PatchMapping
@@ -21,9 +22,8 @@ class UserController(
 ) {
     @Operation(summary = "내 정보 조회")
     @GetMapping("/me")
-    fun getMyProfile(
-        @AuthenticationPrincipal userId: Long,
-    ): ResponseEntity<ApiResponse<UserResponse>> {
+    fun getMyProfile(authentication: Authentication): ResponseEntity<ApiResponse<UserResponse>> {
+        val userId = authentication.getUserId()
         val userProfile = userService.getUserProfileById(userId)
         return ResponseEntity.ok(ApiResponse("내 정보를 성공적으로 조회했습니다.", userProfile))
     }
@@ -31,18 +31,18 @@ class UserController(
     @Operation(summary = "내 프로필 수정")
     @PatchMapping("/me")
     fun updateMyProfile(
-        @AuthenticationPrincipal userId: Long,
+        authentication: Authentication,
         @RequestBody request: UserUpdateRequest,
     ): ResponseEntity<ApiResponse<UserResponse>> {
+        val userId = authentication.getUserId()
         val updatedProfile = userService.updateUserProfile(userId, request)
         return ResponseEntity.ok(ApiResponse("정보가 성공적으로 수정되었습니다.", updatedProfile))
     }
 
     @Operation(summary = "회원 탈퇴")
     @DeleteMapping("/me")
-    fun deleteMe(
-        @AuthenticationPrincipal userId: Long,
-    ): ResponseEntity<ApiResponse<Unit>> {
+    fun deleteMe(authentication: Authentication): ResponseEntity<ApiResponse<Unit>> {
+        val userId = authentication.getUserId()
         userService.deleteUser(userId)
         return ResponseEntity.ok(ApiResponse("회원 탈퇴가 완료되었습니다."))
     }